Commit 8082d50f authored Mar 22, 2021 by Shenming Lu Committed by Marc Zyngier Mar 24, 2021

KVM: arm64: GICv4.1: Give a chance to save VLPI state



Before GICv4.1, we don't have direct access to the VLPI state. So
we simply let it fail early when encountering any VLPI in saving.

But now we don't have to return -EACCES directly if on GICv4.1. Let’s
change the hard code and give a chance to save the VLPI state (and
preserve the UAPI).

Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210322060158.1584-7-lushenming@huawei.com

parent 12df7429

Documentation/virt/kvm/devices/arm-vgic-its.rst

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -80,7 +80,7 @@ KVM_DEV_ARM_VGIC_GRP_CTRL
	-EFAULT Invalid guest ram access		-EFAULT Invalid guest ram access
	-EBUSY One or more VCPUS are running		-EBUSY One or more VCPUS are running
	-EACCES The virtual ITS is backed by a physical GICv4 ITS, and the		-EACCES The virtual ITS is backed by a physical GICv4 ITS, and the
	state is not available		state is not available without GICv4.1
	======= ==========================================================		======= ==========================================================

	KVM_DEV_ARM_VGIC_GRP_ITS_REGS		KVM_DEV_ARM_VGIC_GRP_ITS_REGS

arch/arm64/kvm/vgic/vgic-its.c

+3 −3

Original line number	Original line	Diff line number	Diff line
	@@ -2218,10 +2218,10 @@ static int vgic_its_save_itt(struct vgic_its its, struct its_device device)
	/*		/*
	* If an LPI carries the HW bit, this means that this		* If an LPI carries the HW bit, this means that this
	* interrupt is controlled by GICv4, and we do not		* interrupt is controlled by GICv4, and we do not
	* have direct access to that state. Let's simply fail		* have direct access to that state without GICv4.1.
	* the save operation...		* Let's simply fail the save operation...
	*/		*/
	if (ite->irq->hw)		if (ite->irq->hw && !kvm_vgic_global_state.has_gicv4_1)
	return -EACCES;		return -EACCES;

	ret = vgic_its_save_ite(its, device, ite, gpa, ite_esz);		ret = vgic_its_save_ite(its, device, ite, gpa, ite_esz);